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// SPDX-License-Identifier: GPL-2.0
/*
* Apple SoC SPMI device driver
*
* Copyright The Asahi Linux Contributors
*
* Inspired by:
* OpenBSD support Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
* Correllium support Copyright (C) 2021 Corellium LLC
* hisi-spmi-controller.c
* spmi-pmic-ard.c Copyright (c) 2021, The Linux Foundation.
*/
#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/spmi.h>
/* SPMI Controller Registers */
#define SPMI_STATUS_REG 0
#define SPMI_CMD_REG 0x4
#define SPMI_RSP_REG 0x8
#define SPMI_RX_FIFO_EMPTY BIT(24)
#define SPMI_TX_FIFO_EMPTY BIT(8)
/* Apple SPMI controler */
struct apple_spmi {
void __iomem *regs;
struct spmi_controller *ctrl;
};
static inline u32 read_reg(struct apple_spmi *spmi, int offset)
{
return (readl_relaxed(spmi->regs + offset));
}
static inline void write_reg(u32 value, struct apple_spmi *spmi, int offset)
{
writel_relaxed(value, spmi->regs + offset);
}
static int spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 slave_id,
u16 slave_addr, u8 *__buf, size_t bc)
{
struct apple_spmi *spmi;
u32 spmi_cmd = opc | slave_id << 8 | slave_addr << 16 | (bc - 1) |
(1 << 15);
u32 rsp;
volatile u32 status;
size_t len_to_read;
u8 i;
spmi = spmi_controller_get_drvdata(ctrl);
write_reg(spmi_cmd, spmi, SPMI_CMD_REG);
/* Wait for Rx FIFO to have something */
/* Quite ugly msleep, need to find a better way to do it */
i = 0;
do {
status = read_reg(spmi, SPMI_STATUS_REG);
msleep(10);
i += 1;
} while ((status & SPMI_RX_FIFO_EMPTY) && i < 5);
if (i >= 5) {
dev_err(&ctrl->dev,
"spmi_read_cmd:took to long to get the status");
return -1;
}
/* Read SPMI reply status */
rsp = read_reg(spmi, SPMI_RSP_REG);
len_to_read = 0;
/* Read SPMI data reply */
while (!(status & SPMI_RX_FIFO_EMPTY) && (len_to_read < bc)) {
rsp = read_reg(spmi, SPMI_RSP_REG);
i = 0;
while ((len_to_read < bc) && (i < 4)) {
__buf[len_to_read++] = ((0xff << (8 * i)) & rsp) >>
(8 * i);
i += 1;
}
}
return 0;
}
static int spmi_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 slave_id,
u16 slave_addr, const u8 *__buf, size_t bc)
{
struct apple_spmi *spmi;
u32 spmi_cmd = opc | slave_id << 8 | slave_addr << 16 | (bc - 1) |
(1 << 15);
volatile u32 rsp;
volatile u32 status;
size_t i = 0, j;
spmi = spmi_controller_get_drvdata(ctrl);
write_reg(spmi_cmd, spmi, SPMI_CMD_REG);
while (i < bc) {
j = 0;
spmi_cmd = 0;
while ((j < 4) & (i < bc)) {
spmi_cmd |= __buf[i++] << (j++ * 8);
}
write_reg(spmi_cmd, spmi, SPMI_CMD_REG);
}
/* Wait for Rx FIFO to have something */
/* Quite ugly msleep, need to find a better way to do it */
i = 0;
do {
status = read_reg(spmi, SPMI_STATUS_REG);
msleep(10);
i += 1;
} while ((status & SPMI_RX_FIFO_EMPTY) && i < 5);
if (i >= 5) {
dev_err(&ctrl->dev,
"spmi_write_cmd:took to long to get the status");
return -1;
}
rsp = read_reg(spmi, SPMI_RSP_REG);
(void)rsp; // TODO: check stuff here
return 0;
}
static int spmi_controller_probe(struct platform_device *pdev)
{
struct apple_spmi *spmi;
struct spmi_controller *ctrl;
int ret;
ctrl = spmi_controller_alloc(&pdev->dev, sizeof(struct apple_spmi));
if (IS_ERR(ctrl)) {
dev_err_probe(&pdev->dev, PTR_ERR(ctrl),
"Can't allocate spmi_controller data\n");
return -ENOMEM;
}
spmi = spmi_controller_get_drvdata(ctrl);
spmi->ctrl = ctrl;
platform_set_drvdata(pdev, ctrl);
spmi->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(spmi->regs)) {
dev_err_probe(&pdev->dev, PTR_ERR(spmi->regs),
"Can't get ioremap regs.\n");
return PTR_ERR(spmi->regs);
}
ctrl->dev.of_node = of_node_get(pdev->dev.of_node);
/* Callbacks */
ctrl->read_cmd = spmi_read_cmd;
ctrl->write_cmd = spmi_write_cmd;
ret = spmi_controller_add(ctrl);
if (ret) {
dev_err(&pdev->dev,
"spmi_controller_add failed with error %d!\n", ret);
goto err_put_controller;
}
/* Let's look for other nodes in device tree like the rtc */
ret = devm_of_platform_populate(&pdev->dev);
if (ret) {
dev_err(&pdev->dev,
"spmi_controller_probe: devm_of_platform_populate failed with error %d!\n",
ret);
goto err_devm_of_platform_populate;
}
return 0;
err_put_controller:
spmi_controller_put(ctrl);
err_devm_of_platform_populate:
return ret;
}
static int spmi_del_controller(struct platform_device *pdev)
{
struct spmi_controller *ctrl = platform_get_drvdata(pdev);
spmi_controller_remove(ctrl);
spmi_controller_put(ctrl);
return 0;
}
static const struct of_device_id spmi_controller_match_table[] = {
{
.compatible = "apple,spmi",
},
{}
};
MODULE_DEVICE_TABLE(of, spmi_controller_match_table);
static struct platform_driver spmi_controller_driver = {
.probe = spmi_controller_probe,
.remove = spmi_del_controller,
.driver = {
.name = "apple-spmi",
.owner = THIS_MODULE,
.of_match_table = spmi_controller_match_table,
},
};
module_platform_driver(spmi_controller_driver);
MODULE_AUTHOR("Jean-Francois Bortolotti <jeff@borto.fr>");
MODULE_DESCRIPTION("Apple SoC SPMI driver");
MODULE_LICENSE("GPL");
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